﻿using System;

namespace h31
{
    class Program
    {
        static void Main(string[] args)
        {
            Solution solution=new Solution();
            int [] [] ins=new int[3][];
            ins[0] = new[] {1, 2};
            ins[1] = new[] {2, 3};
            ins[2] = new[] {2, 4};
            int ans = solution.EraseOverlapIntervals(ins);
            Console.WriteLine(ans);
        }
    }
}